Messages in this thread Patch in this message | | | Subject | [PATCH] memory hotplug: fix page_zone() calculation in test_pages_isolated() | From | Gerald Schaefer <> | Date | Wed, 29 Oct 2008 15:25:30 +0100 |
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From: Gerald Schaefer <gerald.schaefer@de.ibm.com>
My last bugfix here (adding zone->lock) introduced a new problem: Using page_zone(pfn_to_page(pfn)) to get the zone after the for() loop is wrong. pfn will then be >= end_pfn, which may be in a different zone or not present at all. This may lead to an addressing exception in page_zone() or spin_lock_irqsave().
Now I use __first_valid_page() again after the loop to find a valid page for page_zone().
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
--- mm/page_isolation.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
Index: linux-2.6/mm/page_isolation.c =================================================================== --- linux-2.6.orig/mm/page_isolation.c +++ linux-2.6/mm/page_isolation.c @@ -130,10 +130,11 @@ int test_pages_isolated(unsigned long st if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE) break; } - if (pfn < end_pfn) + page = __first_valid_page(start_pfn, end_pfn - start_pfn); + if ((pfn < end_pfn) || !page) return -EBUSY; /* Check all pages are free or Marked as ISOLATED */ - zone = page_zone(pfn_to_page(pfn)); + zone = page_zone(page); spin_lock_irqsave(&zone->lock, flags); ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn); spin_unlock_irqrestore(&zone->lock, flags);
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